GB354314A - Improvements in or relating to sewing machines - Google Patents

Abstract

354,314. Sewing-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. and BATES, A., Union Works, Belgrave Road, Leicester. May 6, 1930, No. 13836. [Class 112.] Chain-stitching by barbed needles.-The needle movements are automatically varied according to the speed of the machine to avoid reeving or breaking the thread. The invention is specially applicable to the boot-sole sewing machine described in Specification 13873/10, [Class 112, Sewing &c.], which operates at different speeds according to whether the machine is sewing along sides or round the toe or heel. The needle 1 is carried by the usual carrier 3 swung round its pivot 5 by the arm 7 actuated by the member 11 pivoted on the shaft 15. The member 11 is actuated by a roller 19 travelling in a cam track 21 in the member 23 mounted on the main shaft. A weighted arm 39 is pivoted on the cam and is swung outwards centrifugally against the spring 33 when the main shaft exceeds a certain speed. This causes an arm 25, mounted on a stud on the arm 39, to overlay a portion of the cam track 21, as shown in Fig. 3, so diverting the roller 19 into a new path and automatically slowing down the needle in its withdrawal from the work and easing the thread tension. The feeding mechanism is the same as that described in Specifications 115,235, [Class 112, Sewing &c.]. The tension device is as described in Specification 28985/10, [Class 112, Sewing &c.].